f9ea8ba5e
Jason A. Donenfeld
2022-04-24
Subject
seedrng: code-golf even smaller
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util-linux/seedrng.c+14 -28
| @@ -102,7 +102,7 @@ static int read_new_seed(uint8_t *seed, size_t len, bool *is_creditable) | |
| }; | |
| if (random_fd.fd < 0) | |
| return -1; | |
| - | *is_creditable = safe_poll(&random_fd, 1, 0) == 1; |
| + | *is_creditable = poll(&random_fd, 1, 0) == 1; |
| close(random_fd.fd); | |
| } else if (getrandom(seed, len, GRND_INSECURE) == (ssize_t)len) | |
| return 0; | |
| @@ -174,15 +174,13 @@ int seedrng_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE; | |
| int seedrng_main(int argc UNUSED_PARAM, char *argv[]) | |
| { | |
| const char *seed_dir = DEFAULT_SEED_DIR, *creditable_seed, *non_creditable_seed; | |
| - | int ret, fd = -1, dfd = -1, program_ret = 0; |
| + | int fd, dfd, program_ret = 0; |
| uint8_t new_seed[MAX_SEED_LEN]; | |
| size_t new_seed_len; | |
| - | bool new_seed_creditable; |
| - | bool skip_credit = false; |
| + | bool new_seed_creditable, skip_credit = false; |
| struct timespec timestamp = { 0 }; | |
| sha256_ctx_t hash; | |
| - | int opt; |
| enum { | |
| OPT_d = (1 << 0), | |
| OPT_n = (1 << 1) | |
| @@ -194,8 +192,7 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) | |
| ; | |
| #endif | |
| - | opt = getopt32long(argv, "d:n", longopts, &seed_dir); |
| - | skip_credit = opt & OPT_n; |
| + | skip_credit = getopt32long(argv, "d:n", longopts, &seed_dir) & OPT_n; |
| creditable_seed = concat_path_file(seed_dir, CREDITABLE_SEED_NAME); | |
| non_creditable_seed = concat_path_file(seed_dir, NON_CREDITABLE_SEED_NAME); | |
| @@ -207,11 +204,8 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) | |
| bb_perror_msg_and_die("unable to %s seed directory", "create"); | |
| dfd = open(seed_dir, O_DIRECTORY | O_RDONLY); | |
| - | if (dfd < 0 || flock(dfd, LOCK_EX) < 0) { |
| - | bb_perror_msg("unable to %s seed directory", "lock"); |
| - | program_ret = 1; |
| - | goto out; |
| - | } |
| + | if (dfd < 0 || flock(dfd, LOCK_EX) < 0) |
| + | bb_perror_msg_and_die("unable to %s seed directory", "lock"); |
| sha256_begin(&hash); | |
| sha256_hash(&hash, "SeedRNG v1 Old+New Prefix", 25); | |
| @@ -220,16 +214,14 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) | |
| clock_gettime(CLOCK_BOOTTIME, ×tamp); | |
| sha256_hash(&hash, ×tamp, sizeof(timestamp)); | |
| - | ret = seed_from_file_if_exists(non_creditable_seed, dfd, false, &hash); |
| - | if (ret < 0) |
| - | program_ret |= 1 << 1; |
| - | ret = seed_from_file_if_exists(creditable_seed, dfd, !skip_credit, &hash); |
| - | if (ret < 0) |
| - | program_ret |= 1 << 2; |
| + | for (int i = 1; i < 3; ++i) { |
| + | if (seed_from_file_if_exists(i == 1 ? non_creditable_seed : creditable_seed, |
| + | dfd, i == 1 ? false : !skip_credit, &hash) < 0) |
| + | program_ret |= 1 << i; |
| + | } |
| new_seed_len = determine_optimal_seed_len(); | |
| - | ret = read_new_seed(new_seed, new_seed_len, &new_seed_creditable); |
| - | if (ret < 0) { |
| + | if (read_new_seed(new_seed, new_seed_len, &new_seed_creditable) < 0) { |
| bb_perror_msg("unable to%s seed", " read new"); | |
| new_seed_len = SHA256_OUTSIZE; | |
| memset(new_seed, 0, SHA256_OUTSIZE); | |
| @@ -243,17 +235,11 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[]) | |
| fd = open(non_creditable_seed, O_WRONLY | O_CREAT | O_TRUNC, 0400); | |
| if (fd < 0 || full_write(fd, new_seed, new_seed_len) != (ssize_t)new_seed_len || fsync(fd) < 0) { | |
| bb_perror_msg("unable to%s seed", " write"); | |
| - | program_ret |= 1 << 4; |
| - | goto out; |
| + | return program_ret | (1 << 4); |
| } | |
| if (new_seed_creditable && rename(non_creditable_seed, creditable_seed) < 0) { | |
| bb_simple_perror_msg("unable to make new seed creditable"); | |
| - | program_ret |= 1 << 5; |
| + | return program_ret | (1 << 5); |
| } | |
| - | out: |
| - | if (ENABLE_FEATURE_CLEAN_UP && fd >= 0) |
| - | close(fd); |
| - | if (ENABLE_FEATURE_CLEAN_UP && dfd >= 0) |
| - | close(dfd); |
| return program_ret; | |
| } | |